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Code Issues Releases Wiki Activity

s390: add support for KFENCE 

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
[hca@linux.ibm.com: simplify/rework code]
Link: https://lore.kernel.org/r/20210728190254.3921642-4-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Sven Schnelle 2021-07-28 21:02:53 +02:00 committed by Heiko Carstens
parent f99e12b21b
commit e41ba1115a
5 changed files with 54 additions and 4 deletions
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1
arch/s390/Kconfig
View File

@ -138,6 +138,7 @@ config S390
select HAVE_ARCH_JUMP_LABEL_RELATIVE
select HAVE_ARCH_KASAN
select HAVE_ARCH_KASAN_VMALLOC
select HAVE_ARCH_KFENCE
select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_SOFT_DIRTY

42
arch/s390/include/asm/kfence.h Normal file
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@ -0,0 +1,42 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_S390_KFENCE_H
#define _ASM_S390_KFENCE_H
#include <linux/mm.h>
#include <linux/kfence.h>
#include <asm/set_memory.h>
#include <asm/page.h>
void __kernel_map_pages(struct page *page, int numpages, int enable);
static __always_inline bool arch_kfence_init_pool(void)
{
return true;
}
#define arch_kfence_test_address(addr) ((addr) & PAGE_MASK)
/*
* Do not split kfence pool to 4k mapping with arch_kfence_init_pool(),
* but earlier where page table allocations still happen with memblock.
* Reason is that arch_kfence_init_pool() gets called when the system
* is still in a limbo state - disabling and enabling bottom halves is
* not yet allowed, but that is what our page_table_alloc() would do.
*/
static __always_inline void kfence_split_mapping(void)
{
#ifdef CONFIG_KFENCE
unsigned long pool_pages = KFENCE_POOL_SIZE >> PAGE_SHIFT;
set_memory_4k((unsigned long)__kfence_pool, pool_pages);
#endif
}
static inline bool kfence_protect_page(unsigned long addr, bool protect)
{
__kernel_map_pages(virt_to_page(addr), 1, !protect);
return true;
}
#endif /* _ASM_S390_KFENCE_H */

9
arch/s390/mm/fault.c
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@ -31,6 +31,7 @@
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/hugetlb.h>
#include <linux/kfence.h>
#include <asm/asm-offsets.h>
#include <asm/diag.h>
#include <asm/gmap.h>
@ -356,6 +357,7 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
unsigned long address;
unsigned int flags;
vm_fault_t fault;
bool is_write;
tsk = current;
/*
@ -369,6 +371,8 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
mm = tsk->mm;
trans_exc_code = regs->int_parm_long;
address = trans_exc_code & __FAIL_ADDR_MASK;
is_write = (trans_exc_code & store_indication) == 0x400;
/*
* Verify that the fault happened in user space, that
@ -379,6 +383,8 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
type = get_fault_type(regs);
switch (type) {
case KERNEL_FAULT:
if (kfence_handle_page_fault(address, is_write, regs))
return 0;
goto out;
case USER_FAULT:
case GMAP_FAULT:
@ -387,12 +393,11 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
break;
}
address = trans_exc_code & __FAIL_ADDR_MASK;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
flags = FAULT_FLAG_DEFAULT;
if (user_mode(regs))
flags |= FAULT_FLAG_USER;
if (access == VM_WRITE || (trans_exc_code & store_indication) == 0x400)
if (access == VM_WRITE || is_write)
flags |= FAULT_FLAG_WRITE;
mmap_read_lock(mm);

3
arch/s390/mm/init.c
View File

@ -34,6 +34,7 @@
#include <asm/processor.h>
#include <linux/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/kfence.h>
#include <asm/ptdump.h>
#include <asm/dma.h>
#include <asm/lowcore.h>
@ -200,7 +201,7 @@ void __init mem_init(void)
high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
pv_init();
kfence_split_mapping();
/* Setup guest page hinting */
cmma_init();

3
arch/s390/mm/pageattr.c
View File

@ -8,6 +8,7 @@
#include <asm/cacheflush.h>
#include <asm/facility.h>
#include <asm/pgalloc.h>
#include <asm/kfence.h>
#include <asm/page.h>
#include <asm/set_memory.h>
@ -326,7 +327,7 @@ int __set_memory(unsigned long addr, int numpages, unsigned long flags)
return change_page_attr(addr, addr + numpages * PAGE_SIZE, flags);
}
#ifdef CONFIG_DEBUG_PAGEALLOC
#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)
static void ipte_range(pte_t *pte, unsigned long address, int nr)
{